Runoff is the life blood to any garden and is a valuable data set that every grower should be using. How you collect runoff and what you use it for will ensure you stay consistent during all stages of growth and development.
If you are growing in any cube, pot or container it’s important that every watering be long enough to produce ~10% runoff. You don’t need to collect runoff from every single plant but you do want a good random sample from different areas of the growing environment.
Runoff samples are only beneficial if they are collected properly. It’s critical that meters are calibrated and trays are clean. If you have salt buildup in your collection trays it’s very easy to get an inaccurate reading. Inaccurate readings will lead to incorrect decisions about what should be happen next.
To get an accurate overview, we want to collect samples from ~5% of the plants in the room. Make sure these samples are from different areas in the growing environment and all genetics are accounted for. Take these samples and combine them into a single container. Use your meters (EC and pH) to analyze the combined samples.